try fixing reset instead

vaadin-grid-flow-parent/vaadin-grid-flow/src/main/resources/META-INF/resources/frontend/gridConnector.ts

@@ -542,27 +542,6 @@ window.Vaadin.Flow.gridConnector.initLazy = (grid) => {
     }
   };
 
-  /**
-   * Update the given page of items in the DOM, if the items are visible
-   */
-  const updatePageInDom = function (pageItems) {
-    const firstItem = pageItems[0];
-    if (!firstItem) {
-      return;
-    }
-
-    // Item might not be in grid cache yet if there is a pending request for that page
-    const firstItemContext = dataProviderController.getItemContext(firstItem);
-    if (!firstItemContext) {
-      return;
-    }
-
-    // Update the visible rows in the grid
-    const flatStartIndex = firstItemContext.flatIndex;
-    const flatEndIndex = flatStartIndex + pageItems.length - 1;
-    grid.__updateVisibleRows(flatStartIndex, flatEndIndex);
-  };
-
   grid.$connector.set = function (index, items, parentKey) {
     if (index % grid.pageSize != 0) {
       throw 'Got new data to index ' + index + ' which is not aligned with the page size of ' + grid.pageSize;
@@ -588,9 +567,11 @@ window.Vaadin.Flow.gridConnector.initLazy = (grid) => {
       grid.$connector.doSelection(slice.filter((item) => item.selected));
       grid.$connector.doDeselection(slice.filter((item) => !item.selected && selectedKeys[item.key]));
 
-      updateGridCache(page, pkey);
-      itemsUpdated(slice);
-      updatePageInDom(slice);
+      const updatedItems = updateGridCache(page, pkey);
+      if (updatedItems) {
+        itemsUpdated(updatedItems);
+        updateGridItemsInDomBasedOnCache(updatedItems);
+      }
     }
   };
 
@@ -752,7 +733,6 @@ window.Vaadin.Flow.gridConnector.initLazy = (grid) => {
   };
 
   grid.$connector.reset = function () {
-    grid.size = 0;
     cache = {};
     dataProviderController.rootCache.items = [];
     lastRequestedRanges = {};